Oil burner control apparatus



Jan. 2, 1940. E. c. RANEY on. BURNER CONTROL Amnurfis Filed Nov. 18, 1935 TOR ATTOR N EY V 4 w 7. mi W 2 Y 7. B Y F- 7 m M u 8 6 a 0 1 4 vi 2 H 1 Jan. 2, 1940. Q RANEY 2,185,752

onjmmumz con-r1101. APPARATUS Filed Nov. 18, 1936 3 Sheets-Sheet 3 I 4 III 155 .114 v W INVETOR g5? v fmffl,

ATTORNEY Patented Jan 2 1940' UNITED STATES OIL BURNER APPARATUS Estel 0. l tancy, Columbus, Ohio, assignor '-to Rance Incorporated, Columbus, Ohio, a vcor.-

' poration of Ohio' Application November re, 1936, Serial No. 111,480 3'; Claims. (01.. 158-28) My invention relates to control'systems andmore particularly to (electricahcontrol circuits and mechanism for -controlling fuel burning apparatus. 7

One of the objects of the present invention is to provide a control systeni for fuel burning apparatus in which various controlsare rendered effective and ineffective in a preselected sequence, when the fuel burner functions-in the normal manner, and which co'ntrol'system preventsdamage to the system in the event of any abnormal condition. In carrying out this object is is a further object of the present inventionto provide a controller-including a timing device and driv- 15 ing mechanism therefor, in which the driving mechanism is controlled by temperatures of the room to beheated and by combustion temperatures; to provide for connecting the driving mechanism-with the timing device for starting the system; to prevent the driving'mechanism from operating the timing device during the demand for heat from the fuel burning apparatus; to provide for disconnectingthe driving mechanism from the timing device after the'demand for heat has been satisfied so thatthe timer is in condition for restarting the fuel burning'apparatus upon reoccurrence of a demand for heat; to provide for the simultaneous flow of current forthe burner motor and for the electric ignition and for discontinuing; the ignition after apredetermined time while continuing the supply of current forthe'burner motor; to prevent reoccurrence of ignition except during the starting operation; and for rendering the system inoper- 3 ative in the event of failure of combustion. Another object isijto provide a timing device for such a system in which the time interval for operation of the same can be adjusted.

Other and further objects and advantages will 4 be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the present invention is clearly shown- In the drawings:

iii Fig]. 1 is a schematic diagram of acontrol-sys-.

tem as applied to an oil burning system; the controller for the system is shown durin a P riod of non-operation: 1

Fig. 2 is a'schematic diagram of the system 50 showing the controller during a normal operating period: 1 v

Fig. 3 is a diagram similar toFig. 2 but showing the controller in the position before deenergization due to failure of combustion;

Fig. 4 isv a new similar to Fig, 2 after the system has-beendeener'gized due; 'I "'failureof com- Fig. 5 is a sectional view taken on the lineH ,,of Fi'g .4

ignite the fuel therefrom.

I Fig. 6 isaside elevatiohal view of the controller motor and its gearing:

Fig.7 is a'sectional view of the timing device showing the return spring and timing adjustment and,

Fig. 8 is asctionalview taken on line 8-8 of.

Fig. A.

An embodiment of my invention is shown in Fig. 1, wherein the control system is utilized to control an oil burning system. A furnace i8 is provided with, a combustion chamber and an associated electrically driven fuel feeding device 22, which may be a motor-blower. The operation of the system is controlled by a controller 24, which includes a timing device 26 and a driving motor 28 therefor. The timing device 26 is disposed to operate a plurality of control switches, in a preselected sequence, for initiating and stopping the various functions'of the system. A room thermostat 30 controls the normal operation of the system by causing the driving motor 28 to operate thetiming device 26 when there is a demand for heat, and by. causing the system tq' cease operation when the demand for heat is satisfied. A stack, or combustion control, generally indicated at 32, is provided to cause the systein to stop operation, when an emergency condition occurs; such as a fuel failure, or a failure to establish combustion. A spark'plug 34, or other type of igniting means; is positioned adjacent-the discharge of motor-blower 22 to The system includes two circuits. namely a control'circuit for the fuel feeding device 22, and for an ignition coil and a secondary control circuit that includes the room thermostat 30. The first mentioned circuit may be traced as follows: current is Supplied by power lines 36 and 38; line- 36 is connected directly to a primary winding 40 of a transformer 42, line 36 is also connected by wire 44 to a primary 46 of the ignition coil 35 and to the motor-blower 22. The other line 38, -'is connected by a, flexible connection to an emergency switch 50, which includes contacts 52 and 54. A block 56, of conductive material, electrically connects the switch .50 to a spring contact member, which carries contact 62. The member 64 is supported atone end- It will be noted that the cur- .former 42.- Thus the transformer primary 40 is constantly. energized when theemergency switch is closed, which is the normal position of the switch. The division of curient that passes through switch 68, traverses the member 64 and divides, part passing by wire 68 to the motorhlower .22. and the other part passing through a switch 58, which includes contacts 60, 62 and I unitary with the gear wire 10, switch I2, wire 14, switch I6, and wire I8 to the primary 46 of the ignition coil. Thus when switches 50 and 58 are closed the motorblower is energized. The energization of the ignition coil 36 however, is dependent on the concurrent closure of the switches 50, 58, I2 and I6. From the foregoing it is apparent that the switch 50 controls the entire system.

.The secondary control circuit includes'a secondary winding 80 of the transformer 42, the room thermostat 30 and an elec-tro-magnet 82. The circuit is as follows; secondary winding 80, wire 84, thermostat 30, wire 86, coil 88 of electro-magnet 82, wire 90 to the secondary 80. Thus the secondary circuit is a closed circuit, which is controlled entirely by the opening and closing of the thermostat 30.

The primary 40 of the transformer 42 is wound directly on the field core of the controller motor 28, which motor is preferably of the shaded pole type. The primary 40 is utilized as the field winding for the motor 28. The secondary winding 80 of the transformer 42 is also wound on the core of the motor 28 which core is utilized as the core for the transformer. Since the primary winding 40 which is also the field for the motor 28, is constantly energized, it is apparent that the motor 28 is always capable of rotation.

In order to selectively control the operation of the motor 28, means are provided for preventing the operation of the motor. This means includes two friction brakes, 92 and 94 respectively. The brake 92 includes a substantially L shaped lever 96, the upturned end, or leg, of which is designated at 98. The leg 98 is disposed to frictionally engage the periphery of a disc I00, which disc is carried by the shaft of the motor 28. The lever 96 is pivoted at I02 and weighted by a weight I04 at the end opposite the upturned leg 98.: Thus the lever 96 pivots around its bearing I02, due to the weight I04 and causes the leg 98 to bear, or dragon the periphery of they disc I00. In this position, therefore, the brake 92 provides sufiicient retarding force to stop the rotation of the motor 28. The weight I04 is disposed sufiici'ently close to the magnet 82, so that when the magnet 82 is energized, there is sufiicient magnetic force to attract the weighted end of the lever 96 and remove the brake from the disc I09. Thus when the secondary control circuit is complete, due to the closure of the thermostat 30, the motor 28 is operative.

The motor 28 is engaged to the timing device 26 during operating periods of the system by reducing gearing. The motor 28 is directly engaged to gears I06, I08, H and H2, while the timing device 26. is directly engaged to gears H4, H6 and H6. The gear I I6 is substantially H8. The gears, H6 and H8 are fixedly mounted and spaced on a hub I20, and the gear I I2 is journalled on the hub I between the gears H6 and H8. The gears H2 and H8 are of substantially the same diam eter and pitch. In order to operatively engage the motor 28 and timing device a relatively wide enga ng gear I22 is provided which is adapted to be meshed with the gears H2 and H8 simultaneously. The gear I22 is carried by the lever 96, so that when the secondary control circuit is closed and the lever 96 is raised at its weighted end by the magnet 82, the gear I22 meshes with gears H2 and H8 to actively engage the motor and the timing device. It is apparent therefore that the gearing is only engaged when the brake 92 is removed to allow rotation of the motor 28.

The timing device 26 is provided with a projection or spur I26 which engages the spring member 64 of switch 58 and separates the contacts 60 and 62, when the system is not operating. When the thermostat calls for heat and completes the secondary control circuit, the brake 92 is removed from the controller motor 28 and the motor and timing device are engaged and the latter starts to rotate in a clockwise direction. As the timing device 26 revolves it displaces the spur I26 from engagement with member 64, which caused the switch 58 to close. Closure of the switch 58 simultaneously completes two circuits, first it energizes the fuel feeding device or motor-blower 22, and secondly it completes the circuit to the ignition coil 35. This last circuit it will be noted is broken by switch I6 when the lever 96 is in brakingbustion chamber and the ignition means there--- fore are rendered operative.

The combustion responsive control 32 is positioned so that its thermal element; is afiected by temperature changes in the chamber 20, caused by the establishment of combustion. One form of thermal responsive combustion control is shown, which utilizes a bellows I28 connected by a capillary tube H with a bulb I9 filled with a suitable volatile fiuid and located in the combustion chamber 20. An increase in temperature within the chamber 20, causes the bellows I28 to elongate, which change in length is transmitted to a lever I30. The lever I 30 is pivoted at one end thereof and connected to a spring I32 at the other end. The spring causes the lever I30 to be in constant engagement with the bellows I28. Stops I34 are provided to limit the movement of the lever in either direction. Thus the lever is against the upper stop I 34 when the system is inoperative and against the lower stop I 34 when the system is operative, this last position being caused by displacement due to elongation of the bellows I28 to force the lever I30 downwardly as is shown in Fig. 2.

During the initial operating, or heating up period of the system, the timing device 26 is rotated slowly by the motor 28 until a stop I 40, on the timing device, engages a projection I42 disposed on a member I44, slidably mounted on guides I6. The member I44 is biased by 'a spring I46 to resist lateral movement of the lever as imparted by the stop I40. However the member I 44 is displaced tothe right, as viewed in Fig. 1, by the movement of stop I until a projection I48 on the member I44 engages the switch I2,

to open the switch .12 and'break the ignition circuit. In this manner the ignition coil 35 is only energized for a predetermined time period after the closure of switch 58.

The outer end of the member I44 carries a pivotly mounted lever I 50. 'The lower end of lever I50 is disposed to ride on the periphery of the disc I00. As the slidable member I44 is moved to a position beyond the position required to open switch I2, the upper end of lever I50 engages the end of downwardly displaced lever I 30 of the stack control. This fixedly positions the upper end of the lever I50 and further movement of lever I44 causes the lower end of member I50 to drag on the disc I00 sufiiciently to cause the motor 28 to stop. Thus the brake, generally indicated at 04, is applied when the system is functioning properly as illustrated in Fig. 2. If the fuel does not ignite, the stack control 52 remains inoperative. Inthis case the lever I30 of the stack control is not interposed to stop the inward movement of member I44 and apply the brake 94, and the timing device 26 will continue to rotate until the inner end of the displaced member I44 engages the emergency switch 50 to cause separation of contacts 52 and 54. As the contacts separate the contact lever I52 of switch is drawn downwardly by a spring I54. A pin I56, in an elongated slot I58, limits the down- 18 ward movement of the-lever I52. When contacts energized and operation cannot be resumed until lever I52 has been manually reset to re-engage' contacts 52 and 54. The described position is shown in Fig. 4.

This same action occurs if the flame should become extinguished or the 'fuel supply should fail, during a normal operating period. The only diiiference being the lever I50 would necessarily have to be drawn out of engagement with the upper end of the'lever I50. This movement of lever I50 would occur due to cooling and retraction of the bellows of the combustion control 32. At the instant the levers I50 and I50 are disengaged the brake 54 is released and the motor and timing device can resume operation until the switch 50 has been operated as previously described. Thus if any emergency arises, either during a starting operation, or during a normal operating cycle, the system is completely de-energized Whenever the system has been deenergized either by the emergency operation of switch 50, or by the normal action of the thermostat 00, the lever 56 drops to the position shown in Fig. 1. This disconnects the gearing .between the motor 20 and the timing device 26. As the lever 06 drops, a pin I mounted onthe lever separates the contacts of switch I6 to break the ignition circuit. Simultaneously with the disengagement of the motor and timing device, the timing device 26 is rotated counterclockwise to its starting position. This is accomplished by a spiral spring I55 iixedly attached to the timing device at one end thereof and anchored at its other end. Thus the spring I55 is wound upior increased in tension. as the timing'device rotates in a clockwise direction. When the timing device is disengaged this spring I55 unwinds and returns the timing device to itsstarting l fi tion with spur I26 en- 06 gaging, and separating the contacts of switch 58. v In this manner the system is in position for a subsequent operation. The switch I6 is provided to prevent reoccurrence of ignition as the timing 5 gised. This condition would be dangerous in the" event the-flame had become extinguished and the thermostat 50 had opened the circuit to flame'extinguishmenthadoccurred. Inthiscasethe combustion chamber 20 would be charged Y 1. with ignitible fuel and the energization of the ignition circuit would cause aniesplosion. The provisionof switch I6 assures butone occurrence of ignition ;during cycle of operation. In

52 and 54 are separated the entire system is dedesired temperatures.

other words the timing device 26 must come back to its starting position before the ignition coil can be energized.

The position of the stop I40 on the timing device 26 determines the time period of operation of the ignition circuit and of the timing device. These periods may be varied by raising the stop I40 against a compression spring I51 and reset tingv the stop in any one of the plurality of holes I which are provided around the circumference of the timing device 26. In this manner the angle of rotation of the timing device may be changed to vary the time period of operation.

From the foregoing it will be noted that I have,

provided a complete and automatic fuel control system that not only initiates combustion, but maintains the same under control to provide The system includes a safety control to check the establishment andmaintenanceof combustion; it also includes a time controlled ignition device for igniting the fuel; which ignition cannot re-occur except during the starting operation of the system. Thus the system is controlled for normal operation and also is controlled to assure safety during abnormal or emergency operation.

While the formof embodiment of the present. invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adapted, all coming within the scope of the claims which follow. I

I claim:

1. In a control system for a fuel burning apparatus, a circuit for controlling theoperation of. the apparatus; a switch in the circuit; a timing device, operable after a predetermined period of energization of the circuit, for opening the switch, said timing device including anelectric motor constantly energizedwhen the circuit is energized and constantly tending to actuate the device; means responsive to the establishment of combustion; a friction brake for stalling the timing device; and mechanism actuated by the timing device, after a predetermined operation of the device and rendered eflective by the means. for actuating the brake to stall the timing device.

2. In a control system for a fuel burning apparatus, a circuit for controlling the operation of the apparatus; a device including an electric motor energized constantly during a demand on a the fuel burning apparatus; a switch in said circuit opened by the device after a predetermined operation of the device; means responsive to the establishment of combustion; a friction brake for stalling themotor; and mechanism "actuated by the device, after a predetermined operation of the device and rendered effective by the means, for actuating the brake to stallthe motor.

3.. In a control system for a fuel burning -ap-' paratus, a circuit for controlling-the operation of the apparatus; switching means in-the circuit; a timing device for actuating the switching means, said timing device including a continuously energized electric motor and mechanism for actuating the switching means. said mechanism being adapted to be driven by the motor; deenergize the system-at some time after the means for connecting and disconnecting the motor from th'e'mechanism in response to temperature changes; and a brake for stalling the motor, said brake being actuated by :the last mentioned means to stall the motor when the motor is disconnected from the 1 mm C. BANIY. 

